Concrete Works, Here is the Complete guide

Concrete works involve the execution of the placement of concrete into the structures which are to be constructed. There are various steps involved in the placement of concrete that are required to be understood by all the stakeholders before the start of the activity.

Usually, it is a project/client requirement for the submission & approval of a method statement for every activity which is going to be executed. This article covers all the important references, literature & step by step procedures for executing concrete work at the site.

Reference Documents

Applicable Project specifications and documents related to this method statement are:

• Project Quality Plan
• Civil Quality Plan
• EHS Plan
• Specifications/Approved drawings
• Site Instructions as issued by client/consultant

Summary of Equipment

The following equipment will be used for the scope of work covered under this method of statement.

1. Power Generators
2. Concrete tank truck
3. Concrete pump
4. Concrete vibrator
5. Wheel
6. Auto Level
7. Shovel Spade Cone Grab hoe Level etc.
8. Concrete site testing equipment.

Method for Concrete Works

Manpower Requirement

• Project Manager
• Civil Engineer
• Site Engineer
• Site Supervisor
• Skilled/unskilled labor
• Helpers
• EHS Supervisor

All the power tools should be operated by competent persons.

The sequence of the Work

Detailed procedures of Concrete Works

• Get permission from the client before starting work.
• Get the RFI’s for formwork & steel fixing approved by the Client.
• Ensure that concrete chutes/funnels are available at the site & fixed at designated locations as per the concrete pouring plan.
• Ensure that wood debris and sundries in the formwork have been cleaned through vacuum cleaners & electric blower & the area is free from pieces of binding wires.
• Spray / pour concrete bonding agent between fresh old concrete joints/keys.
• Selection of vibrator shaft as per the concrete requirement.

Ensure that concrete free fall height shall not be greater than 1.5m in order to avoid segregation

On-Site Testing of Concrete Before Placement

Following tests are to be conducted before the placement of concrete in the formwork.

• Slump Test of concrete
• Temperature check
• Casting of cubes / Cylinders for compressive strength checks at 14 & 28 days.

Wall concrete placement:

Wall concrete pouring should be layered, should be separated as far as possible to prevent concrete segregation. Concrete should be poured in layers and vibrated, and the pouring thickness of each layer should be controlled at about 600mm. Pouring of wall concrete should be continuous, the interval time should be as short as possible, and should be in the front layer of concrete before the initial coagulation of the second layer of concrete pouring is finished. In the process of concrete pouring and vibration, the steel bar shall not be moved at will, and the thickness of the steel bar protection layer and the firmness and position accuracy of all embedded parts shall be checked frequently.

Floor slab concrete works:

When the floor slab concrete is pouring, it should be vibrated by a plug-in vibrator. The concrete is dragged diagonally by the plug-in vibrator to ensure that the concrete design requires and compaction In the process of pouring, the elevation should be controlled by pulling wires to meet the design requirements.

After completion of concrete final setting, curing shall be started off.

Concrete works of frame structure

The multi-layer frame is constructed according to the layered and segmented construction, the horizontal direction is segmented according to the expansion joint of the structure plane, and the vertical direction is layered according to the structure hierarchy. On each floor first pouring stair, column, then pouring beam, plate. The steel bar at the joint of beam and column is relatively dense. Before concrete pouring, the distribution of the steel bar should be fully understood. During concrete pouring, the thickness of the concrete protective layer and the position of the steel bar should be ensured. The original positions of embedded parts and reserved holes shall not be moved. If any deviation or displacement is found, it shall be timely corrected

For larger lengths of columns to be poured in a single go, shall be treated especially & concrete shall not be directly poured from a relatively greater height. Such cases shall be discussed with the Client at the site before execution

• Ensure that concrete temperature shall not exceed 320C by taking remedial measures while for hot weather concreting limit the maximum concrete temperature to 350C (ACI 305.1–14)
• The measure for hot weather concrete if it allows the concrete temperature to exceed up to 35 degrees.
• Moisten subgrade, steel reinforcement, and formwork prior to concrete placement.
• In extreme conditions consider adjusting the time of concrete placement to take advantage of cooler temperatures, such as early morning or night time placement.
• Provide appropriate curing methods as soon as possible after the concrete finishing processes have been completed.
• All measures for site testing of concrete shall be arranged.
• Concrete pouring shall be strictly monitored to be completed in the design retardation time from concrete batching time.

Risk Assessment

The contractor should control all and not be limited to the following listed hazards during construction

1

Concrete leakage

Conveying pump to transport concrete, pipe joint safety valve must be in good condition, the pipe shelf must be firm, before transportation must be tested, maintenance must be pressure relief.

2

Electric shock

When using the vibrator, wet hands shall not touch the switch, the power cord shall not be damaged and leakage, the switch shall be installed with a protection device to prevent leakage.

3

Electric leakage

1. The power cord of the vibrator shall not be used to mop the ground or as a tractor tool.

2. Operators must wear insulating rubber shoes and insulating rubber gloves.

4

The pumped concrete frame is unsecured.

The project manager shall conduct safety training and technical disclosure to the operators before they go on duty. When the frame is finished. must check and ensure safety.

Conclusion

This article is all about the method for placement of concrete works at the site. Thank you for reading the complete blog post. If you have any comments please write us. For interesting facts about concrete please watch on youtube, Click here

Originally published at https://intotheboxes.com on November 30, 2021.